Abstract: Despite the debilitating nature of addiction, and its associated societal and economic cost, there is currently no effective treatment. Here we propose to develop a bold new approach to the rampant neural plasticity induced by drugs of abuse. Although drug-induced plasticity is thought to be at the heart of the disease, it has not been possible to design circuit- level therapies to counteract these plastic changes because of technological limitations. My lab is now uniquely positioned to finally innovate such an approach, because of our expertise in both counteract the new field of optogenetics (the optical control of neural activity) and the emerging analysis of circuit-level mechanisms underlying addiction. To create this new approach to counteract addiction-related behavior, we will develop a novel panel of next-generation technologies togenetically and functionally target selected cell-types in rats. In order to counteract drug-induced plasticity, we will apply the new targeting technologies to activate the aversion and extinction in synchrony with the circuits that encode the drug experience, thereby circuits involved in weakening the drug-related associations and alleviating addiction-related behavior. Thus, we present here both a powerful new concept for the treatment of addiction, as well as the development of enabling technologies to achieve this vision. Public Health Relevance: Addiction is a devastating illness which destroys the lives of millions of people in the United States, is associated with enormous economic and societal cost, and is virtually without treatment. By developing a panel of new technologies designed to control neural activity in the appropriate cell-types in a rodent model of addiction, we open the door to the development of an exciting new approach to counteract drug-induced plasticity and addiction-related behavior.